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Copyright ©The Author(s) 2020. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Biol Chem. Nov 27, 2020; 11(3): 76-98
Published online Nov 27, 2020. doi: 10.4331/wjbc.v11.i3.76
Current understanding of glucose transporter 4 expression and functional mechanisms
Tiannan Wang, Jing Wang, Xinge Hu, Xian-Ju Huang, Guo-Xun Chen
Tiannan Wang, Xinge Hu, Guo-Xun Chen, Department of Nutrition, The University of Tennessee, Knoxville, TN 37996, United States
Jing Wang, Xian-Ju Huang, College of Pharmacy, South-Central University for Nationalities, Wuhan 430074, Hubei Province, China
Author contributions: Wang T, Wang J and Hu X conducted the PubMed Search; Wang T, Wang J, Hu X, Huang XJ and Chen GX outlined and wrote the manuscript.
Conflict-of-interest statement: All authors declare that there is no conflict of interest to report.
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/Licenses/by-nc/4.0/
Corresponding author: Guo-Xun Chen, PhD, Associate Professor, Department of Nutrition, The University of Tennessee, Room 229 Jessie Harris Building, 1215 West Cumberland Avenue Knoxville, TN 37996, United States. gchen6@utk.edu
Received: June 26, 2020
Peer-review started: June 26, 2020
First decision: August 9, 2020
Revised: August 22, 2020
Accepted: September 22, 2020
Article in press: September 22, 2020
Published online: November 27, 2020
Processing time: 137 Days and 14.8 Hours
Abstract

Glucose is used aerobically and anaerobically to generate energy for cells. Glucose transporters (GLUTs) are transmembrane proteins that transport glucose across the cell membrane. Insulin promotes glucose utilization in part through promoting glucose entry into the skeletal and adipose tissues. This has been thought to be achieved through insulin-induced GLUT4 translocation from intracellular compartments to the cell membrane, which increases the overall rate of glucose flux into a cell. The insulin-induced GLUT4 translocation has been investigated extensively. Recently, significant progress has been made in our understanding of GLUT4 expression and translocation. Here, we summarized the methods and reagents used to determine the expression levels of Slc2a4 mRNA and GLUT4 protein, and GLUT4 translocation in the skeletal muscle, adipose tissues, heart and brain. Overall, a variety of methods such real-time polymerase chain reaction, immunohistochemistry, fluorescence microscopy, fusion proteins, stable cell line and transgenic animals have been used to answer particular questions related to GLUT4 system and insulin action. It seems that insulin-induced GLUT4 translocation can be observed in the heart and brain in addition to the skeletal muscle and adipocytes. Hormones other than insulin can induce GLUT4 translocation. Clearly, more studies of GLUT4 are warranted in the future to advance of our understanding of glucose homeostasis.

Keywords: Glucose transporter 4; Insulin; Skeletal muscle; Adipocytes; Brain; Heart; Antibodies

Core Tip: Glucose transporter 4 (GLUT4) can be detected not only in the skeletal muscle and adipocytes, but also in the brain and heart. In addition to the translocation from vesicles in the cytosol to the cell membrane by insulin, the expression levels of Slc2a4 mRNA and GLUT4 proteins are also regulated by many factors. A variety of methods and antibodies from various sources have been used to evaluate GLUT4 expression and translocation.